While buying an airport, why no airport map delivered with runways and taxiways data, as well as gate numbers

Well, I do not need the latest airport layout for simulation flying. At least I would like to have a correct map of the correct taxiways etc. with the product bought/delivered… For the simple airport Danang it has cost me 1 hour in MS-word to add the correct taxi ways etc., convert it to Acrobat and get it in my ebag…
But to find out which is which is the real problem. The modellers have this info…